rijndael (all) , and blowfish (128)
are already in gnupg, and have been for many versions

would like to see serpent included
(have been using it in truecrypt, and don't find it 'slow'
at all,
[but then, i'm an old 3des fan, so anything else is faster
;-)],
and eventually, when truecrypt allows decryption of a container
with a key, it would be nice to have,
although they have a quite 'good enough' selection now)

am not familiar with skipjack or kea
or any particular advantage that they would offer

(serpent is considered to be very 'solid' but slower than
rijndael)

at his point, though,
it would probably need to be a decision by the open pgp group
to adopt it,
before gnupg would unilaterally include it,

and unless they find some great 'must have' quality,
it probably 'won't be included any time soon ;-(